I know what you're going through because I lived it. You can read my story here:
http://www.soberrecovery.com/forums/...u-so-much.html
My advice is to walk away, feel all the emotions as you go through the heartbreak/grieving process, and then focus on yourself. Look out for you, and only you. Try to find your own happiness. Let him be an addict. You don't need that in your life. Would you tolerate a boyfriend who wasn't an addict stealing from you? Then why tolerate a boyfriend who is an addict stealing from you? You deserve better. He sounds like he's a damaged man. You can't help him. He can only help himself. *hugs*